Document how to add multi-arch support for the docker and podman templates

### Description

Building for another architecture gets an error:

`exec /bin/sh: exec format error`

Currently there is documentation for containerd

https://lima-vm.io/docs/config/multi-arch/#fast-mode

----

Might need entries also for docker and podman:

`limactl shell docker sudo apt install -y qemu-user-static`

`limactl shell podman sudo dnf install -y qemu-user-static`

And some basic example with `--platform linux/amd64`

Might also need qemu-user-binfmt or something, verify that the packages actually enable the binfmt_misc entries:

```
/proc/sys/fs/binfmt_misc
```

It needs to be static to work in containers, otherwise it might have dependencies on host libraries that are unavailable.

i.e. it works for regular binaries in the VM